Social enterprises will play an important role in creating new jobs over the next few years. Unemployment levels are high, and unless we see a huge boom in the private sector it is unlikely that long-term unemployed people will find work simply by applying for vacancies advertised in the Job Centre.

It is particularly hard for those with a criminal record, so a group of social enterprises in Bristol are coming together to create a significant number of new jobs for ex-offenders through the repair and refurbishment of empty properties.

Getting a new venture off the ground is hard work. We are putting together an investment prospectus with the help of Triodos, an ethical bank, which will be aimed at investors who are probably already significant donors to charity but who may be prepared to invest for social good.

Our aim is to finance the purchase of empty properties and create the jobs through the repair and refurbishment. The capital is recycled over a five year period and offers our investors a modest rate of return.

There will be some secondary benefits too. Not only will we create much-needed jobs, but in some cases we will use the empty properties we bring back into use to provide accommodation for people in desperate need of a secure roof over their head.

We have already run a successful pilot project, based on a similar idea, and developed by the Restore Trust, a social enterprise that has spun out of the Probation Service. It has created job placements for more than 70 ex-offenders, and repaired empty council houses in Bristol that will now be brought back into use. Our aim is to take the lessons from that pilot project and develop a sustainable way of funding this activity for years to come.

I hope I will be able to draw upon the lessons I learnt setting up Aspire more than 10 years ago. Aspire was a social enterprise that created jobs for people who were homeless or had a recent history of homelessness. My friend, Mark Richardson, and I set it up together after we left university. It is fair to say we didn't really know what we were doing and made an awful lot of mistakes.

We were desperate to create as many jobs as we could – after all the demand from those out of work was huge. But we did not lay proper foundations, such as having a strong board of directors in place, raising sufficient working capital, or really road-testing our business model before we started employing homeless people. As such, the business was unstable from almost the first day of operation.

We believed that we could create jobs for some of the most excluded groups of people in the country, and at the same time grow a profitable social enterprise, expand it across the UK, make a large return for investors, and need no grant funding at all. It was a hopelessly optimistic scenario – and we let down a lot of people who bought into that vision. Nor did we help our fellow social entrepreneurs by forcefully advocating a business model that we would not be able to replicate.

More careful planning in the early days, and a later launch with a more experienced management team, could have made every possible difference. But we shall never know. Part of the attraction of Aspire was that it was an instinctive and passionate response to a social need. Time spent planning was (in our view) time spent while people were languishing on the streets.

Paradoxically, although we had not even begun our careers, we felt we had no time to waste. But that enthusiasm was also an asset. Our vision – in all its naivety – caught the imagination of many people, and we eventually brought them on board to strengthen the organisation, in a way that a more balanced and cautious project might not have done. If we hadn't helped hundreds of people into work then I doubt Tony Blair would have chosen Aspire as a project to visit when he highlighted the success of his government's rough sleeping strategy. Yet for all our outward success, and in many ways it was considerable, we were haemorrhaging cash at the same time as we were opening up new centres across the UK.

We aimed for the stars and crashed to earth well short of our aims. But something tangible was achieved; and, after several false starts and rescue plans, Aspire has continued and strengthened over the past 11 years. The current management of Aspire deserve enormous credit for taking the concept Mark and I developed and turning it into a social enterprise that has now helped hundreds more people off the streets and into work, and operating it for several years now on a more sustainable basis.

So I am relishing the challenge of applying the lessons I have learnt to this new venture, and hopefully developing a new model that will offer an even greater chance of success.

This time I shall ensure that we have a strong board in place from the start. Their insight and strategic overview will be invaluable. We shall also ensure that the investment proposition is more robust – and having Triodos on side will be crucial with that. I also believe that working in partnership with other social enterprises is the way forward – building upon what others have already achieved, rather than trying to do something new just for the sake of it.

Finally I hope I am a little wiser, and I am certainly older. I would never discourage a 21-year-old from starting up a social enterprise, but I would be disappointed if I do not fare a little better now that I am 34.

I am convinced that social enterprises need to be at the forefront of job creation – and partnerships such as the one we are developing in Bristol could be an excellent way forward. Watch this space.

Paul Harrod was the co-founder of Aspire, a social enterprise that creates employment for homeless people. He left his role as chief executive in 2003 and is now working in partnership with other social enterprises on a new venture

This content is brought to you by Guardian Professional. To get more articles like this direct to your inbox, sign up to the social enterprise network.